On Sat, 2007-08-11 at 20:23 -0400, Bob Goodwin wrote: > Tim wrote: > > On Sat, 2007-08-11 at 16:46 -0400, Bob Goodwin wrote: > > > >> I installed two new SLA batteries two days ago and judging from the > >> voltage across the terminals it was charging. I would have to remove > >> the case to measure battery voltage which ought to be near 27 volts by > >> this time I would think. > >> > > > > My preference for checking that batteries are charging is measuring the > > current going to them, rather than voltage. But that's not always > > practical, heavy charge can be quite a few amps, and it may drop down to > > just a few milliamps when (almost) done. That's quite a range to cover > > with just one meter. > > > > > Yes, if I have to kludge together a charger for a drill battery or some > such I use a variable bench supply and measure the drop across a series > resistor and tweak things periodically. This thing doesn't lend itself > to measuring the current and it would be out of range for my old Fluke. > > I took the cover off and checked, it was up to 26.9 volts and dropped > back to 24.6 after a bit connected to a 21" tv/cctv deal I have to help > the feeble of eye read text. It's good, and I found an item in the > configuration I could set to make it ignore the [false] low battery charge. > > I want to try "nut" also and see if it works any better. > > Gel cells require a different charging potential and charge currents than immersion type (conventional lead acid) storage batteries. Most systems for chargers have a strap of some kind to set for "flooded" (conventional) or "gel" for gell cells. Regards, Les H
